The general objective of this research is the study of the structure of proteins of biological interest and of examination of the reactivity of these proteins towards chemical reagents of defined specificity. Emphasis will be placed on complete characterization of the naturally occurring and altered proteins with the ultimate aim of defining some of the stereochemical relationships among the reaction functional groups. It is hoped that this approach will help to provide some basis for understanding the nature of the catalytic activity and specificity of a protein. We also hope to learn more about the forces acting between protein molecules, and transfer RNA, and we would eventually like to be able to correlate the results obtained from these chemical studies with those obtained by purely physical methods such as X-ray crystallography.